Base64

Comment utiliser Base64

1. 1Enter or paste your data into the input field.
2. 2Select the desired encoding, hashing, or encryption options.
3. 3Click the action button to process your data.
4. 4Copy the result from the output field.

Fonctionnalités

• ✓100% gratuit — sans inscription, sans abonnement, sans publicité
• ✓Fonctionne entièrement dans votre navigateur — vos données ne quittent jamais votre appareil
• ✓Rapide et léger — résultats instantanés
• ✓Multiplateforme — compatible ordinateur, tablette et mobile

Qu'est-ce que Base64 ?

Base64 is a binary-to-text encoding scheme defined by RFC 4648 that converts binary data into a set of 64 ASCII characters (A-Z, a-z, 0-9, +, /). It is NOT encryption — it is fully reversible and requires no key. Base64 is commonly used for MIME email, Data URLs, JWT payloads, and embedding binary resources in JSON/XML.

Comment fonctionne Base64 ?

Base64 processes input data in 3-byte (24-bit) blocks, splitting each block into four 6-bit groups. Each 6-bit value maps to one of 64 characters. If the input length is not divisible by 3, padding (=) is appended. UTF-8 text is first encoded to bytes before Base64 encoding.

Cas d'usage courants

• ✓API token encoding — pass binary tokens safely in HTTP headers
• ✓Email attachments — MIME encodes binary files as Base64 for text-based transport
• ✓Data URLs — embed small images directly in HTML/CSS as Base64 strings
• ✓JWT tokens — the header and payload sections use Base64URL encoding

Base64 vs Encryption

Base64 is encoding; encryption is a different operation. Base64 is reversible by anyone (no key needed) — its purpose is format compatibility, not confidentiality. Encryption (AES, RSA) requires a key and is designed to hide data. Use Base64 when you need to transport binary data through text-only channels; use encryption when you need to protect data from being read.

Sécurité et confidentialité

This tool runs entirely in your browser — your data is never uploaded to any server. Base64 itself provides NO security; never use it to protect sensitive data. For password storage use Bcrypt; for confidentiality use AES encryption.

Détails techniques

Standard: RFC 4648. Character set: A-Z, a-z, 0-9, +, / (URL-safe variant uses - and _). Padding: one or two = characters. A 1MB input produces ~1.33MB Base64 output (33% size increase). Base64URL (used in JWT) replaces +/ with -_ and omits padding.

Questions fréquentes

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